Vector calculus, + finding parametric equation

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SUMMARY

The discussion focuses on finding a set of parametric equations for a line that is perpendicular to another line L1 defined by the equations x=3+2t, y=2t, z=t, and intersects the plane x+3y-z=-4 at point P(1,2,-1). The user successfully calculates the intersection point and derives the normal direction vectors from the plane and line, resulting in a cross product of <-5,3,4>. The final parametric equations for the perpendicular line L2 are given as x=1-5t, y=-2+3t, z=-1+4t. The user expresses uncertainty about the correctness of their solution but receives confirmation that the calculations are accurate.

PREREQUISITES
  • Understanding of vector calculus concepts, specifically parametric equations.
  • Familiarity with cross-product operations in three-dimensional space.
  • Knowledge of how to find intersection points between lines and planes.
  • Ability to manipulate and solve equations involving multiple variables.
NEXT STEPS
  • Study the properties of cross products in vector calculus.
  • Learn how to graph parametric equations in three-dimensional space using software tools like GeoGebra or MATLAB.
  • Explore the geometric interpretation of lines and planes in vector calculus.
  • Practice solving similar problems involving lines and planes to reinforce understanding.
USEFUL FOR

Students studying vector calculus, particularly those focusing on parametric equations and geometric interpretations of lines and planes. This discussion is beneficial for anyone looking to enhance their problem-solving skills in three-dimensional geometry.

CaptainOfSmug
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Homework Statement


The line L
L1: x=3+2t, y=2t, z=t
Intersects the plane x+3y-z=-4 at a point P. Find a set of parametric equations for the line in the same plane that goes through P and is perpendicular to L.

Homework Equations


cross-product
r=r0+t(vector) this is to get in parametric form typically

The Attempt at a Solution


Well let's just say first I'm having trouble visually what this question is asking (is there a program where I can graph this type of stuff in 3 space?)

substituting the values of "L" into the plane equation and then solved for "t" which was -1. I then plugged those values into the parametric equations of the line to get the point of intersection P(1,2,-1)

Here is where I get confused and visually a bit shaky. I decided to use the normal direction vector, I'll call it
"n1" from the plane=<1,3,-1> and "n2" from the line =<2,2,1>
I take the cross product with the resultant vector being <-5,3,4>
So I then use the parametric equation which is: L2 => x=1-5t, y=-2+3t, z=-1+4t

I'm think I'm done at this point because now I have to sets of parametric equations. To check my answer I set
L1 and L2 equal to each other, solved for the variables using elimination and found the intersection point to be the same as I found earlier.

I have no idea if I'm right or wrong, any tips would be helpful! Please don't just tell me the answer, I would prefr someone to point out a mistake and let me figure out the rest, after all, I'm taking math to actually grasp it :)

Thanks in advance!
Cheers
 
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CaptainOfSmug said:

Homework Statement


The line L
L1: x=3+2t, y=2t, z=t
Intersects the plane x+3y-z=-4 at a point P. Find a set of parametric equations for the line in the same plane that goes through P and is perpendicular to L.

Homework Equations


cross-product
r=r0+t(vector) this is to get in parametric form typically

The Attempt at a Solution


Well let's just say first I'm having trouble visually what this question is asking (is there a program where I can graph this type of stuff in 3 space?)

substituting the values of "L" into the plane equation and then solved for "t" which was -1. I then plugged those values into the parametric equations of the line to get the point of intersection P(1,2,-1)

Here is where I get confused and visually a bit shaky. I decided to use the normal direction vector, I'll call it
"n1" from the plane=<1,3,-1> and "n2" from the line =<2,2,1>
I take the cross product with the resultant vector being <-5,3,4>
So I then use the parametric equation which is: L2 => x=1-5t, y=-2+3t, z=-1+4t

I'm think I'm done at this point because now I have to sets of parametric equations. To check my answer I set
L1 and L2 equal to each other, solved for the variables using elimination and found the intersection point to be the same as I found earlier.

I have no idea if I'm right or wrong, any tips would be helpful! Please don't just tell me the answer, I would prefr someone to point out a mistake and let me figure out the rest, after all, I'm taking math to actually grasp it :)

Thanks in advance!
Cheers

The intersection point is <1,-2,-1> but that's just a typo. Looks ok otherwise.
 

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